PDF Watermark and Page Numbers可以处理什么？
PDF Watermark and Page Numbers 用于在浏览器中转换数据或文件，并清楚显示处理结果和限制。 已核对的功能： Unicode watermark text, Adjustable size and opacity, Page N of total labels, Local PDF export.
A visible watermark is not secure redaction
Use this tool to label drafts, review copies, or ownership visibly. Do not use it to hide confidential content: the original page objects remain in the PDF, and a determined editor may be able to remove an overlay.
如何使用？
- Open one unencrypted PDF no larger than the 100 MB browser limit.
- Enter up to 60 watermark characters, choose a size and opacity, and enable or disable Page N of total labels.
- Select Process, review the page count and output size, then download watermarked.pdf.
实际输入输出示例
Mark a twelve-page review copy
输入
Source: draft.pdf (12 pages)
Watermark: INTERNAL REVIEW
Size: 48
Opacity: 0.20
Page numbering: enabled输出
watermarked.pdf
Diagonal watermark on every page
Bottom labels: Page 1 of 12 … Page 12 of 12Text is rendered to a transparent image in the browser, which permits Unicode characters supported by the local system fonts before the image is embedded into each page.
常见错误与修复方法
| 现象 | 可能原因 | 修复方法 |
|---|---|---|
| The PDF cannot be processed. | It is encrypted, damaged, incomplete, or not actually a PDF document. | Use an authorized unlocked copy or export a valid PDF before adding overlays. |
| The watermark is hard to read or covers important content. | Its size or opacity is inappropriate for the page design. | Reduce opacity for dense documents or adjust the size and process the original again. |
Important behavior of PDF Watermark
该工具的实际边界： The watermark is an ordinary visible PDF overlay, not tamper-proof rights management or secure redaction.
标准与实现参考
- pdf-lib documentation (opens in a new tab)Documents the browser-side PDF loading, PNG embedding, opacity, rotation, and save operations used by this workflow.
- MDN — HTMLCanvasElement.toBlob() (opens in a new tab)Documents the local transparent PNG generation step used for Unicode overlay text.
关于PDF Watermark的常见问题
Does the PDF Watermark upload my input?
No. Processing runs in the current browser tab, and the page does not send tool input to a KitLumi processing endpoint.
What input does the PDF Watermark accept?
It accepts one unencrypted PDF, optional watermark text, size and opacity settings, and a page-number choice. The workspace checks the input and reports malformed or unsupported values before it produces a result.
What does the PDF Watermark produce?
It produces a downloadable PDF whose existing pages include the selected overlays. Copy and download controls appear when the output format supports them.
What limitation should I know?
The watermark is an ordinary visible PDF overlay, not tamper-proof rights management or secure redaction.
更新记录
本次实质更新： PDF Watermark: Added Unicode watermark text, Adjustable size and opacity, Page N of total labels, Local PDF export, responsive controls, explicit runtime disclosure, and task-specific examples and limitations.